1. Field of the Invention
This invention concerns a sorting and packing device for sorting and packing eggs such as hen's eggs. More specifically, it relates to an egg sorting and packing device for mixing eggs belonging to several classes on the weight basis beyond the limit for each of the classes of the eggs to thereby obtain packs of a predetermined weight.
2. Discussion of Background
Hen's eggs are sold while being packed, for example, every ten pieces in a container made of plastics based on the weight divisions of SS (greater than 40 g--less than 46 g), S (46 g--less than 52 g), MS (52 g--less than 58 g), M (58 g--less than 64 g), L (64 g--less than 70 g), 2 L (70 g--less than 76 g) and non-standard (76 g--) by the trading standard of the Japanese Ministry of Agriculture Forestry and Fishery office. There are many sorting and packing devices of this type and the disposing performance thereof has been increased year by year.
However, upon selling in supermarkets and the likes, since leading packs for the classes are M and L classes, the unit prices per Kg are higher in the eggs of the M and L classes, while the unit prices per Kg in other classes of eggs ar lower at the present situation. In view of the above, eggs of the M and L classes have been sold by properly mixed with eggs of other classes for making the one pack weight uniform in order to overcome the foregoing evil effect.
As the countermeasure for the above, eggs once classified have been manually mixed and re-packed at present and, accordingly, this increases the cost and also increases the frequency of breaking eggs to thereby make it actually impossible to pack a large amount of them. As a method of successively measuring the weight of lump-like articles with scattered unit weight to thereby obtain a predetermined number of the articles, the total weight of which falls within a certain weight range, although a method as in Japanese Pat. Publication No. Sho 57-29651 has been known, the method is a so-called batchwise method and can not be adopted for the automatic packing of eggs in which they are conveyed in a single row without stopping and treated in a great amount.
The object of this invention is to provide a sorting and packing device for properly selecting and combining eggs without being restricted by the conventional weight-based divisions for each of the classes and packing the eggs so as to fall within the range of a predetermined weight per one pack.